Which devices are used in pre-action systems to trigger the sprinklers?

In pre-action sprinkler systems, the primary devices used to trigger the activation of the sprinklers are smoke detectors and heat responsive devices. These components are designed to detect fire conditions, either through the presence of smoke or by reaching a specific temperature threshold. Once these conditions are detected, a signal is sent to the pre-action system, which then allows water to flow into the piping. This method provides an additional layer of protection compared to traditional systems, as it helps prevent accidental discharge of water while still ensuring a prompt response to real fire events.

The combination of smoke detectors and heat responsive devices allows for a more comprehensive response to different types of fires, ensuring that the sprinkler system activates when necessary while minimizing the risk of false activations.